• Journal of Biosystems Engineering
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• 제20권3호
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• pp.236-244
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• 1995

Droplet size is one of the important factors in the deposition and drift of agrichemical application. In this study, droplet size and its distribution of the three different sizes of ceramic hollow cone nozzles being used in the air carrier sprayer for apple production were investigated at the various nozzle pressures and the three air velocities. The Malvern particle size analyzer were used for the measurement of droplet size and its distribution. The important results emerged from th is study can be summarized as follows. 1. Discharged rate was increase with the increase of the nozzle diameter and pressure, amount of the difference was remarkable between the nozzle diameter of 1.0, 1.2 and 1.5 mm, but no difference were found between the diameter of 1.0 and 1.2 mm in the same nozzle pressure. 2. Mass median diameter were varied as 40~160 ${mu}m$ at the air velocity of 0 m/s, 70~140 ${mu}m$ of 15 m/s and 100~160 ${mu}m$ of 20 m/s 3. It appeared that the air velocity range of 15~20 m/s was desirable for both drift and deposition control in the given experimental conditions.

• 대한기계학회논문집B
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• 제21권1호
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• pp.132-139
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• 1997

Spray characteristics of external mixing sonic twin-fluid atomization nozzles are investigated experimentally. Particle sizes are measured by the Fraunhofer diffraction method using the Malvern particle analyzer, and their radial distributions are obtained using the tomographical transformation technique. The spatial distribution of SMD shows that the drop size increases in the radial direction at a fixed liquid flow rate, and the distribution is getting uniform rapidly as the atomizing gas pressure increases. The SMD decreases as the liquid flow rate increases at a fixed GLR. It is found that the atomization efficiency of the flush type sonic nozzle is superior to that of protrusion type. The effect of laser beam diameter of the particle analyzer on the spatial SMD distribution is minor at present experimental conditions.

• 한국자동차공학회논문집
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• 제4권1호
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• pp.177-186
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• 1996

A convolution alogorithm combined with Fourier transformation is applied to the tomographic reconstruction of the asymmetric spray structure to identify the local drop size and volume concentration. The line of sight intergrated data from Malvern particle analyzer with multiangular scanning form a basic information for the deconvolution. Linear interpolation is tested to obtain the effect of increasing number of scanning angles. This transformation method predicts well the structure of asymmetric spray. The tehnique can be extended to other line of sight combustion diagnostics.

• 한국가시화정보학회지
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• 제2권1호
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• pp.25-31
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• 2004

Droplet size is one of the most important parameter which controls the performance of the combustion system using liquid fuel or oxidizer. Droplet formation and its size are mainly affected by the injection velocity and ambient gas density. Recently, droplet size measurement was conducted by PDPA or Malvern particle analyzer using laser light. But at this paper image processing method was developed to measure droplet size. And its validation was investigated with reticle.

• 대한기계학회논문집B
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• 제21권8호
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• pp.1056-1067
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• 1997

Present study visualized flow pattern and investigated spray characteristics of twin-fluid atomization with converging-diverging nozzles. Particle sizes were measured by using the Malvern particle analyzer, and the radial size distributions were evaluated by using the tomographic transform technique. The results show that the SMD generally increases in the radial direction at a prescribed liquid flow rate and the increasing rate in the SMD becomes gradual as atomizing gas pressure increases. The SMD decreases as the liquid flow rate increases at a fixed GLR (gas/liquid mass ratio). The atomization performance of the protrusion-type nozzle turned out to be superior to that of the flush-type. However, in the case of the protrusion-type, flow separation occurs outside the liquid delivery tube when the pressure at the gas nozzle chamber is high enough, which may deteriorate the atomization performance.

• 대한기계학회논문집B
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• 제20권3호
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• pp.1005-1014
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• 1996

An experimental investigation has been carried out to examine the influence of injector design variables and operating conditions on the resultant drop size for triplet impinging streams injectors. The variables studied in this investigation are pressure drop, impinging angle, orifice length to diameter ratio, and impinging point distance. Droplet-size data are obtained using water as the propellant simulant by Malvern Particle Analyzer System. Drop size decreases with increasing impinging angle and pressure drop while other injector parameters remain constant at the same point. But it is found that there is no noticeable droplet-size change which results from change in orifice length to diameter ratio or impinging point distance within the investigated range.

• Journal of Mechanical Science and Technology
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• 제18권6호
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• pp.1002-1009
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• 2004

Direct contact air conditioning systems, in which heat and mass are transferred directly between air and water droplets, have many advantages over conventional indirect contact systems. The purpose of this research is to investigate the cooling and heating performances of direct contact air conditioning system for various inlet parameters such as air velocity, air temperature, water flow rate and water temperature. The experimental apparatus comprises a wind tunnel, water spray system, scrubber, demister, heater, refrigerator, flow and temperature controller, and data acquisition system. The inlet and outlet conditions of air and water are measured when the air contacts directly with water droplets as a counter flow in the spray section of the wind tunnel, and the heat and mass transfer rates between air and water are calculated. The droplet size of the water sprays is also measured using a Malvern Particle Analyzer. In the cooling conditions, the outlet air temperature and humidity ratio decrease as the water flow rate increases and as the water temperature, air velocity and temperature decrease. On the contrary, the outlet air temperature and humidity ratio increase in the heating conditions as the water flow rate and temperature increase and as the air velocity decreases.

• 핵의학기술
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• 제20권2호
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• pp.36-41
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• 2016

1. 목적 현재 감시림프절 검사에는 $^{99m}Tc-Phytate$만 사용한다. 만약 일시적으로 공급이 중단된다면 대체 가능한 방사성의약품이 없는 실정이다. 본 연구에서는 감시림프절 검사의 성공요소 중 방사성의약품의 입자 크기에 중점을 두어 핵의학 검사에 사용되는 방사성의약품들의 입자크기를 측정해보고 감시림프절 검사 시 $^{99m}Tc-Phytate$를 대체할 수 있는 방사성의약품을 찾아보고자 하였다. 2. 방법 Zetasizer Nano ZS90 (Malvern, UK)를 통하여 체내검사에 이용되는 Phytate, MAG3, DPD, DMSA, MAA, DTPA, HDP의 입자크기를 분석하였다. 동물실험은 9주령의 백서 6마리를 사용하여 각각 3마리씩 $^{99m}Tc-Phytate$를 사용한 대조군과 감시림프절 검사 시 유용하다고 알려진 입자크기를 갖는 $^{99m}Tc-MAG3$, $^{99m}Tc-DPD$와 $^{99m}Tc-DMSA$를 사용한 실험군을 설정 하였다. 백서의 발등에 11.1 MBq ($300{\mu}Ci$)을 인슐린 주사기를 이용하여 피하주사 하고, 동적영상과 정적지연영상을 획득한 후 육안으로 서혜부 림프절을 관찰하였다. 3. 결과 나노입자 분석기를 통하여 측정한 입자크기는 각각 Phytate 105~255 nm ($81.9{\pm}23%$), MAG3 91~255 nm ($98.7{\pm}17%$), DPD 105~342 nm ($77.3{\pm}11%$), DMSA 164~342 nm ($99.2{\pm}35%$), MAA 1281~2305 nm($90.6{\pm}82%$), DTPA 342~1106 nm ($79.4{\pm}28%$), HDP 295~955 nm ($94{\pm}33%$)로 나타났다. $^{99m}Tc-Phytate$를 사용한 대조군은 모든 실험에서 서혜부 림프절을 육안으로 확인 할 수 있었다. $^{99m}Tc-Phytate$와 가장 유사한 크기의 $^{99m}Tc-MAG3$는 서혜부 림프절에 저류하지 않고 빠르게 통과하였고, $^{99m}Tc-DPD$와 $^{99m}Tc-DMSA$를 이용한 실험에서는 서혜부 림프절에 대조군과 비슷하게 저류되어 림프절 관찰이 용이하였다. 결론: 본 실험을 통해서 핵의학 체내검사에 사용되는 방사성의약품들의 입자크기 분포를 확인하였다. $^{99m}Tc-MAG3$는 $^{99m}Tc-Phytate$와 가장 유사한 입자크기를 가지고 있으나 동물실험에서는 서혜부 림프절이 관찰되지 않고 빠르게 신장을 통해 배출되었다. 반면에 $^{99m}Tc-DPD$나 $^{99m}Tc-DMSA$의 경우 유사시 대체 방사성의 약품으로 사용 될 수 있을 것으로 생각된다.

• 공업화학
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• 제9권3호
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• pp.457-461
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• 1998

본 연구에서는 베지클의 응용성을 확장하기 위한 기초연구로서, DPPC(dipalmitoylphosphaticylcholine)/Chol(Cholesterol)계에 불소화계면활성제($C_8F_{17}(CH_2)_2OCO-CH_2CH(SO_3Na)COO(CH_2)_2C_8F_{17}$, FS)/불소화지방산염 (($C_7F_{15}COONH_4$, FFS)을 여러 가지 비율로 변화시켜 첨가함으로써 베지클을 변형 제조하고, 그 물리화학적 성질을 비교측정하였다. 제조된 베지클계에 대한 제타-전위 측정(Zetamaster Particle Electrophoresis Analyzer) 결과, 균일한 전하의 베지클이 형성되는 것으로 확인되었고, 이는 FFS 분자가 FS와 DPPC 사이에서 보조계면활성제로 기능하여 DPPC와 FS의 각 성분이 동일 베지클내에 공존하도록 작용했기 때문으로 풀이된다. 베지클의 입자크기 결정에서는 FFS의 농도가 증가할수록 그 크기가 감소하고, 제타-전위도 음의 값으로 더욱 작아지는 것으로 나타났다. 베지클의 분산도 변화에서도 DPPC/Chol/FS/FFS계의 경우가 DPPC/Chol/FS계에 비해 안정성이 훨씬 큰 것으로 조사되었다. 베지클의 서방유출 실험에서도 막내에 포집된 MB(Methylene Blue)의 유출속도가 DPPC/Chol/FS/FFS계에서 감소된다는 결과를 얻었고, 이는 FFS의 첨가로 인해 막의 유동성이 감소되기 때문으로 풀이된다. 이 결과는 형광방출 측정의 $I_{Excimer}/I_{Monomer}$값에서도 확인되는 것으로 막의 미세점도가 FFS 첨가 베지클에서 증가되는 것으로 나타났다. 단백질로서 알부민에 대한 친화도를 비교한 결과에서는 DPPC/Chol/FS/FFS계의 친화도가 다소 낮아지는 것으로 나타났다. 이들 실험결과에 바탕하여 FFS의 첨가에 의해 DPPC/Chol/FS 베지클계는 더욱 안정하고 균일한 막의 구조를 갖는 리포솜을 형성한다는 결론을 얻었다.